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Female Infanticide: Sexual Selection Influences Heterochronic Processes


This page contains a collection of excerpts from sources used to support Shift Theory, an alternative theory of human evolution. Click here for an introduction to this new and unique theory of evolution.

"There are three societies, accounting for 28 of the populations, which are coded in the Ethnographic Atlas as patrilocal or virilocal (the Yanomamo account for 26 populations). The average sex ratio in the junior age grade for these populations is 142 males per 100 females. Seven of the societies are coded in the Atlas as uxorilocal or neolocal, and the remaining case, the Guana, appear not to be patrilocal. These eight societies account for 20 populations with an average junior sex ratio of 103 males per 100 females. Thus while the warring societies as a whole have an average junior sex ratio of 126:100 it is the patrilocal component of the sample which produces the bias while the nonpatrilocal component shows a nearly even sex ratio. This correlation suggests that there are different cost/benefit ratios for raising daughters, given different residence arrangements. For this sample at least, nonpatrilocal systems do not support female infanticide. ... Divale (1974b) has shown a correlation between external warfare (in the absence of internal war) and matrilocality, and Harris has elsewhere emphasized this correlation (1977), noting also an association between matrilocal residence and a "diminution in preferential female infanticide" (1977:63). " (Hawkes, Kristen (1981) A third explanation for female infanticide. Human Ecology 9,1: pp. 83)

"If parental manipulation of the sex ratio is a device for maximizing reproductive success, parents in poor condition should favor daughters to the same extent that parents in good condition favor sons. If sex-biased infanticide is an example of this strategy to maximixe RD, lower stratum parents are expected to practice male infanticide. The combination of reduced reproductive success for sons in the bottom classes of statuses and the shortage of females in the system as a whole which follows female infanticide at the top produces a situation in which daughters are much more reproductively valuable in the lower strata. Since as Dickemann says "rates of female infancticide approaching 100 percent of all female livebirths may occur at the top, no such intensity of male infanticide appears at the bottom" (1979:325), it cannot be argued that sex-biased infanticide fits the Trivers and Willard model." (Hawkes, Kristen (1981) A third explanation for female infanticide. Human Ecology 9,1: pp. 86)

"Contrary to the Trivers and Willard model, the sex ratio of parents in the poorest condition [in China] seems to be the most strongly biased for sons." (Hawkes, Kristen (1981) A third explanation for female infanticide. Human Ecology 9,1: pp. 84)

"Warefare in band and village societies made the practices of infanticide sex-specific. It encouraged the rearing of sons, whose masculinity was glorified in preparation for combat, and the devaluation of daughters, who did not fight. This in turn led to the limitation of female children by neglect, abuse, and outright killing." (Harris, Marvin (1977) Cannibals and Kings. Vintage Books: New York pp. 58-9) [this quote in tribal as opposed to Indo-European context]

"I am not suggesting that war caused female infanticide or that the practice of female infanticide caused war. Rather, I propose that without reproductive presure neither warfare nor female infanticide wuld have become widespread and that the conjunction of the two represents a savage but uniquely effective solution to the Malthusian dilemma.
Regulation of population growth through the preferential treatment of male infants is a remarkable "triumph'' of culture over nature. A very powerful cultural force was needed to get them to kill or neglect more girls than boys. Warfare supplied this force and motivation because it made the survival of the group contingent on the rearing of combat-ready males. Males were chosen to be taught how to fight because armaments consisted of spears, clubs, bows and arrows, and other hand-held weapons. Hence military success depended upon relative numbers of brawny combatants. For this reason males became socially more valuable than female, and both men and women collaborated in "removing" daughters in order to rear a maximum number of sons." (Harris, Marvin (1977) Cannibals and Kings. Vintage Books: New York pp. 60-61)

"I doubt very much that any human being has ever failed to grasp the elementary truth that to have many men you must start by having many women. The failure of band the village societies to act in conformity with this truth suggests not that warefare was caused by infanticide, or infacticide by warfare, but that both infanticide and warfare, as well as the sexual hierarchy that went with these scourges, were caused by the need to disperse populations and depress their rates of growth." (Harris, Marvin (1977) Cannibals and Kings. Vintage Books: New York p. 64)

"I might add that all women get married, are married young, and married during their entire reproductive period, but not all men are successful in finding wives, and many only do so later in their reproductive life spans. (Chagnon, N.A. (1979) Mate Competition, Favoring Close Kin, and Village Fissioning Among the Yanomamo Indians. In Evolutionary Biology and Human Social Behavior. N. Chagnon & W. Irons, eds. Pp. 97)

"Paternity probability appears to be very high among the Yanomamo, based on paternity exclusion tests conducted by my medical colleagues at the Department of Human Genetics, University of Michigan Medical School. Using several different antigen systems we tested blood saples from parent/offspring triads and, allowing for possible errors due to mislabeling specimens, estimated that the nonpaternity level is about ten percent." (Chagnon, N.A. (1979) Mate Competition, Favoring Close Kin, and Village Fissioning Among the Yanomamo Indians. In Evolutionary Biology and Human Social Behavior. N. Chagnon & W. Irons, eds. Pp. 98)

"In addition, displays of masculinity, such as fighting prowess and "waiter" (ferocity) are admired by Yanomamo women, and particularly aggressive men have an advantage both in soliciting the sxual favor of larger numbers of women as well as depressing the temptation of other men to seduce their wives." (Chagnon, N.A. (1979) Mate Competition, Favoring Close Kin, and Village Fissioning Among the Yanomamo Indians. In Evolutionary Biology and Human Social Behavior. N. Chagnon & W. Irons, eds. Pp. 101)

"Ethnographic discussions of infanticide in all these contexts can be readily found in the anthropological literature (cf. Alexancer 1974; Dickeman 1975). For example, droughts (environmental flux) commonly cited as a reason for infanticide practices (the Australian aborigines; Basedow 1925; Bates 1944). the destruction of malformed infants occurs among the Yanomano (infra) and has been widely reported in the anthropological literature (cf. Dickeman 1975 and references there, as well as Dickemann, this volume, chapter 13). Optimal distribution of parental expenditure may require the spacing of offspring beyond the human physiological potential. With multiple births the destruction of one or more of the newborn is commonly reported (Metraux 1946; Grantzberg 1973; see bibliography in Dickeman 1975 and Dickemann's references, this volume; Alexander 1974). Other anthropologists have noted the taxing problems of parental care and the difficulities in rearing more children then local domestic and economic conditions might permit: Birdsell (1968) has argued that "...children who cannot be reared are frequently conceived and born. The solution is systematic infanticide" " (Chagnon, N.A., et. al. (1979) Sex-Ratio Variation among the Yanomamo Indians In Evolutionary Biology and Human Social Behavior. N. Chagnon & W. Irons, eds. Pp. 294)

"Yanomamo infants, both male and female, are likely to be destroyed at birth or to suffer a higher risk of mortality due to systematic neglect, conscious or unconscious, for a variety of reasons other than a parent's preference for a child of one sex or the other. These include cases of physical abnormality, paternity uncertainty, and problems in the spacing of births." (Chagnon, N.A., et. al. (1979) Sex-Ratio Variation among the Yanomamo Indians In Evolutionary Biology and Human Social Behavior. N. Chagnon & W. Irons, eds. Pp. 303)

"The arrival of a new infant before an existing one has already made it through the initial hazardous years leads some Yanomamo mothers to destroy the newborn in order to enhance the surivival chances of an older, but still heavily dependent, child." (Chagnon, N.A., et. al. (1979) Sex-Ratio Variation among the Yanomamo Indians In Evolutionary Biology and Human Social Behavior. N. Chagnon & W. Irons, eds. Pp. 305)

Birth interval information in Yanomamo society suggesting males killed as often as females. (Chagnon, N.A., et. al. (1979) Sex-Ratio Variation among the Yanomamo Indians In Evolutionary Biology and Human Social Behavior. N. Chagnon & W. Irons, eds. Pp. 306)

"The variations in adult reproductive success and subsequent higher male mortality lead tothe expectation of a correspondingly male-biased sex ratio at birth. Males are represented in the sex ratio at birth reported by the Yanomamo in a ratio of 129 for every 100 females "births." If it is assumed that the true sex ratio of offspring at birth is consistent with the world wide average of 105 (Colombo 1957), it can be estimated that some twenty percent of all female children actually born were destroyed for reasons having to do with parental preferences for male offspring (cf. Neel and Weiss 1975)." (Chagnon, N.A., et. al. (1979) Sex-Ratio Variation among the Yanomamo Indians In Evolutionary Biology and Human Social Behavior. N. Chagnon & W. Irons, eds. Pp. 308)

"However, the average sex ratio of offspring produced by headman (110) is not significantly different than non-headman's (121). The average sex ratio of offspring for headmen does not vary with social status as might be predicted by the Trivers-Willard Theory." (Chagnon, N.A., et. al. (1979) Sex-Ratio Variation among the Yanomamo Indians In Evolutionary Biology and Human Social Behavior. N. Chagnon & W. Irons, eds. Pp. 319)

"Evidence for preferential removal of females is strong enough to have convinced several demographers, and comes from all periods down to the eighteenth century. Medieval British data analyzed by Russell show normal adult sex ratios until the mid-thirteenth century, rising during the fourteenth to a high of 133:100, when the Great Plague epidemic equalized them again, thereafter rising again during the fifteenth centry. These figures refer to landholding members of the population; one sample of sefs maintained a ratio of 170:100 even during the plague years (Russell 1948: 167-168). Such figures refer to adult or to total populations, however, and consequently do not allow the eseparation of preferential female infanticide from other relevant variables, especially differential migration, hypergyny, and differential mortality. The great masculinity of serf ratios, which occurs in several samples, is most likely the result of a high proportion of bachelor males in this lowest-status group, as much as or more than the product of female infanticide." (Dickemann, M. (1979) Female Infanticide, Reproductive Strategies, and Social Stratificaition: A Preliminary Model In Evolutionary Biology and Human Social Behavior. N. Chagnon & W. Irons, eds. Pp. 350)

"Five hundred years later, Renaissance Florentine sex ratios have the same character. In 1427, the city's overall sex ratio was 114:100 (for infants, 118:100), while the dominion as a whole had a ratio of 119:100. Thus the specifically rural ratio must have been even higher. However, the city's wealthy class had a ratio of 124:100 (Trexler 1973a: 100-101). Slightly different computations from the same census (Herlihy 1975) give sex ratios for the city and country of Florence (excluding much of the rural dominion) of 124.5 for infants 0-4 years old, but a decline to 105 by the age group 53-57. This census does not include any clergy of either sex, however. An even higher ratio, 162:100, is reported for the offspring of the French nobility in the late Middle Ages (Russell 1958:19). Thus it appears that high masculinity may have widely characterized both ends of the social scale in medieval and Renaissance Europe. .... For example, tax data from England in 1377 reveal a correlation between size of place and degree of sex-ratio distortion, ranging from 111:100 for places of 25 or fewer inhabitants to 93-95:100 for those over 1000 population. This correlation is offset only by higher masculinity in parts of the boroughs of London, Oxford, Rochester, and York (Russell 1948: 149-156; 1958:17). Urban populations on the continent, especially in northern Europe, also show consistent distortions in favor of females as early as the fourteenth century. The 1449 Nurnberg census reveals a female surplus in both burgher and servant classes, resulting in a total sex ratio of 88:100, contrasting with 109 for the surrounding countryside (Russell 1958: 16-17). (Dickemann, M. (1979) Female Infanticide, Reproductive Strategies, and Social Stratificaition: A Preliminary Model In Evolutionary Biology and Human Social Behavior. N. Chagnon & W. Irons, eds. Pp. 352-3)

"While my sources provide little insight into the operation of hypergyny, the predicted relation between social class and type of marriage exchange occurs widely. Western Europe underwent a transition from earlier Germanic brideprice to dowry as the ideal, beginning in the sixth century and reaching completion by perhaps A.D. 1150, at the same time that dowries came to be requisite for nunnery entrance (Herlihy 1975:9,12; Power 1922: 17). Herlihy has attributed this shift to an excess of women in the later Middle Ages, but it more likely an index of the increasingly rigid feudal structure of the second period of European feudalism. Numerous sources attest to the concern of fathers for the provision of dowries, lest their daughters be socially degraded (Power 1975: 41), and the inflation in dowry size as a result of competition for grooms (Herlihy 1975: 12, 16): the concern of fathers at the birth of baby girls clearly parallels that of Northern India. .... With women retaining control over much of their own dowry wealth, as in the rest of Europe, not only uncles and brothers but aunts and mothers themselves were angaged in this transfer of wealth. But while the mediators in the process here include females, the outcome seems to be the same: long-term transmission of wealth from the maternal to the paternal patriline. The persistence of hypergyny associated with dowry has been documented ethnographically in several traditional local-level class structures" (Dickemann, M. (1979) Female Infanticide, Reproductive Strategies, and Social Stratificaition: A Preliminary Model In Evolutionary Biology and Human Social Behavior. N. Chagnon & W. Irons, eds. Pp. 358-9)

"Surprisingly, however, the findings also seem opposite to what might have been expected. Populations of African origin, whether located today in Africa or the New World, tend to have significantly lower sex ratios at birth, with the highest sex ratios at birth and the greatest degree of adult sexual dimorphism recorded in Amerindian, Asian, and European populations." (Alexander R.D., et. al. (1979) Sexual Dimorphisms and Breeding Systems in Pinnipeds, Ungulates, Primates, and Humans. In Evolutionary Biology and Human Social Behavior. N. Chagnon & W. Irons, eds. p. 421)


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